Spoilage of food has been a problem for centuries. While the sun is the ultimate source of natural energy, whether currently radiant or previously stored, the wavelengths of sunlight in the electromagnetic spectrum cause photo-oxidation of photo-sensitive molecules in food or other ingestible chemicals such as vitamins, pharmaceuticals, etc.
Degradation via photo-oxidation can cause loss of therapeutic or caloric effectiveness, change of color, or change of taste. Use of colorants such green or brown colorants in glass is known as a means to reduce or diminish the effects of photo-oxidation for foods such as beer and fruit juices. The colorants are chosen to absorb visible light in the wall of the glass container in the same wavelength ranges as are absorbed by the photo-sensitive food ingredient(s).